package com.iteye.wwwcomy.compiler;

import java.io.File;
import java.io.FileWriter;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;

import javax.tools.JavaCompiler;
import javax.tools.JavaCompiler.CompilationTask;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;

public class Proxy {
	public static Object newProxyInstance(Class infce, InvocationHandler h)
			throws Exception {
		String methodStr = "";
		String rt = "\r\n";

		Method[] methods = infce.getMethods();
		/*
		 * for(Method m : methods) { methodStr += "@Override" + rt +
		 * "public void " + m.getName() + "() {" + rt +
		 * "   long start = System.currentTimeMillis();" + rt +
		 * "   System.out.println(\"starttime:\" + start);" + rt + "   t." +
		 * m.getName() + "();" + rt +
		 * "   long end = System.currentTimeMillis();" + rt +
		 * "   System.out.println(\"time:\" + (end-start));" + rt + "}"; }
		 */
		for (Method m : methods) {
			methodStr += "@Override" + rt + "public void " + m.getName()
					+ "() {" + rt 
					+ "    try {" + rt 
					+ "    Method md = " + infce.getName() + ".class.getMethod(\"" + m.getName()
					+ "\");" + rt
					+ "    h.invoke(this, md);" + rt
					+ "    }catch(Exception e) {e.printStackTrace();}" + rt +

					"}";
		}

		String src = "package test.compiler;" + rt
				+ "import java.lang.reflect.Method;" + rt
				+ "public class Proxy1 implements " + infce.getName() + "{"
				+ rt + "    public Proxy1(InvocationHandler h) {" + rt
				+ "        this.h = h;" + rt
				+ "    }" + rt +

				"    test.compiler.InvocationHandler h;" + rt +

				methodStr + "}";
		String fileName = "src/test/compiler/Proxy1.java";
		File f = new File(fileName);
		FileWriter fw = new FileWriter(f);
		fw.write(src);
		fw.flush();
		fw.close();

		// compile
		JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
		StandardJavaFileManager fileMgr = compiler.getStandardFileManager(null,
				null, null);
		Iterable units = fileMgr.getJavaFileObjects(fileName);
		CompilationTask t = compiler.getTask(null, fileMgr, null, null, null,
				units);
		t.call();
		fileMgr.close();

		// load into memory and create an instance
		URL[] urls = new URL[] { new URL("file:/"
				+ System.getProperty("user.dir") + "/src/") };
		URLClassLoader ul = new URLClassLoader(urls);
		Class c = ul.loadClass("test.compiler.Proxy1");
		System.out.println(c);

		Constructor ctr = c.getConstructor(InvocationHandler.class);
		Object m = ctr.newInstance(h);
		// m.move();

		return m;
	}
}
